Calculation of downlink positioning reference signal (prs) symbol duration for prs buffering purposes

ABSTRACT

Disclosed are techniques for wireless communication. In an aspect, a user equipment (UE) receives at least one positioning reference signal (PRS) resource from a reference transmission-reception point (TRP) and one or more neighboring TRPs, and processes the at least one PRS resource during a time window, wherein a length of the time window is less than or equal to an integer number of orthogonal frequency division multiplexing (OFDM) symbols of the at least one PRS resource that the UE is capable of processing, buffering, or both within the time window.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application for patent claims the benefit of U.S.Provisional Application No. 63/010,426, entitled “CALCULATION OFDOWNLINK POSITIONING REFERENCE SIGNAL (PRS) SYMBOL DURATION FOR PRSBUFFERING PURPOSES,” filed Apr. 15, 2020, assigned to the assigneehereof, and expressly incorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks), a third-generation (3G) high speeddata, Internet-capable wireless service and a fourth-generation (4G)service (e.g., Long Term Evolution (LTE) or WiMax). There are presentlymany different types of wireless communication systems in use, includingcellular and personal communications service (PCS) systems. Examples ofknown cellular systems include the cellular analog advanced mobile phonesystem (AMPS), and digital cellular systems based on code divisionmultiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), the Global System for Mobilecommunications (GSM), etc.

A fifth generation (5G) wireless standard, referred to as New Radio(NR), calls for higher data transfer speeds, greater numbers ofconnections, and better coverage, among other improvements. The 5Gstandard, according to the Next Generation Mobile Networks Alliance, isdesigned to provide data rates of several tens of megabits per second toeach of tens of thousands of users, with 1 gigabit per second to tens ofworkers on an office floor. Several hundreds of thousands ofsimultaneous connections should be supported in order to support largesensor deployments. Consequently, the spectral efficiency of 5G mobilecommunications should be significantly enhanced compared to the current4G standard. Furthermore, signaling efficiencies should be enhanced andlatency should be substantially reduced compared to current standards.

SUMMARY

The following presents a simplified summary relating to one or moreaspects disclosed herein. Thus, the following summary should not beconsidered an extensive overview relating to all contemplated aspects,nor should the following summary be considered to identify key orcritical elements relating to all contemplated aspects or to delineatethe scope associated with any particular aspect. Accordingly, thefollowing summary has the sole purpose to present certain conceptsrelating to one or more aspects relating to the mechanisms disclosedherein in a simplified form to precede the detailed descriptionpresented below.

In an aspect, a method of wireless communication performed by a userequipment (UE) includes receiving at least one positioning referencesignal (PRS) resource from a reference transmission-reception point(TRP) and one or more neighboring TRPs; and processing the at least onePRS resource during a time window, wherein a length of the time windowis less than or equal to an integer number of orthogonal frequencydivision multiplexing (OFDM) symbols of the at least one PRS resourcethat the UE is capable of processing, buffering, or both within the timewindow.

In an aspect, a user equipment (UE) includes a memory; a transceiver;and at least one processor communicatively coupled to the memory and thetransceiver, the at least one processor configured to: receive, via thetransceiver, at least one positioning reference signal (PRS) resourcefrom a reference transmission-reception point (TRP) and one or moreneighboring TRPs; and process the at least one PRS resource during atime window, wherein a length of the time window is less than or equalto an integer number of orthogonal frequency division multiplexing(OFDM) symbols of the at least one PRS resource that the UE is capableof processing, buffering, or both within the time window.

In an aspect, a user equipment (UE) includes means for receiving atleast one positioning reference signal (PRS) resource from a referencetransmission-reception point (TRP) and one or more neighboring TRPs; andmeans for processing the at least one PRS resource during a time window,wherein a length of the time window is less than or equal to an integernumber of orthogonal frequency division multiplexing (OFDM) symbols ofthe at least one PRS resource that the UE is capable of processing,buffering, or both within the time window.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a user equipment(UE), cause the UE to: receive at least one positioning reference signal(PRS) resource from a reference transmission-reception point (TRP) andone or more neighboring TRPs; and process the at least one PRS resourceduring a time window, wherein a length of the time window is less thanor equal to an integer number of orthogonal frequency divisionmultiplexing (OFDM) symbols of the at least one PRS resource that the UEis capable of processing, buffering, or both within the time window.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates an example wireless communications system, accordingto aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures,according to aspects of the disclosure.

FIGS. 3A, 3B, and 3C are simplified block diagrams of several sampleaspects of components that may be employed in a user equipment (UE), abase station, and a network entity, respectively, and configured tosupport communications as taught herein.

FIGS. 4A and 4B are diagrams illustrating example frame structures andchannels within the frame structures, according to aspects of thedisclosure.

FIG. 5 is a diagram of an example radio frequency (RF) signal processingprocedure, according to aspects of the disclosure.

FIG. 6 is a diagram illustrating an example of slot-based positioningreference signal (PRS) processing, according to aspects of thedisclosure.

FIG. 7 is a diagram illustrating an example of slot-based buffering withsymbol alignment towards the largest interval that contains potentialPRS in a slot, according to aspects of the disclosure.

FIG. 8 is a diagram illustrating another example of slot-based bufferingwith symbol alignment towards the largest interval that containspotential PRS in a slot, according to aspects of the disclosure.

FIG. 9 is a diagram illustrating an example of a symbol-level PRSduration to be buffered, according to aspects of the disclosure.

FIG. 10 is a diagram illustrating another example of a symbol-level PRSduration to be buffered, according to aspects of the disclosure.

FIG. 11 is a diagram illustrating an example of slot-based buffering fora slot that has two disjoint intervals with potential PRS symbols at thestart and end of the slot, according to aspects of the disclosure.

FIG. 12 illustrates an example method of wireless communication,according to aspects of the disclosure.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description andrelated drawings directed to various examples provided for illustrationpurposes. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Those of skill in the art will appreciate that the information andsignals described below may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the description below may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof, depending inpart on the particular application, in part on the desired design, inpart on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

As used herein, the terms “user equipment” (UE) and “base station” arenot intended to be specific or otherwise limited to any particular radioaccess technology (RAT), unless otherwise noted. In general, a UE may beany wireless communication device (e.g., a mobile phone, router, tabletcomputer, laptop computer, consumer asset locating device, wearable(e.g., smartwatch, glasses, augmented reality (AR)/virtual reality (VR)headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.),Internet of Things (IoT) device, etc.) used by a user to communicateover a wireless communications network. A UE may be mobile or may (e.g.,at certain times) be stationary, and may communicate with a radio accessnetwork (RAN). As used herein, the term “UE” may be referred tointerchangeably as an “access terminal” or “AT,” a “client device,” a“wireless device,” a “subscriber device,” a “subscriber terminal,” a“subscriber station,” a “user terminal” or “UT,” a “mobile device,” a“mobile terminal,” a “mobile station,” or variations thereof. Generally,UEs can communicate with a core network via a RAN, and through the corenetwork the UEs can be connected with external networks such as theInternet and with other UEs. Of course, other mechanisms of connectingto the core network and/or the Internet are also possible for the UEs,such as over wired access networks, wireless local area network (WLAN)networks (e.g., based on the Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 specification, etc.) and so on.

A base station may operate according to one of several RATs incommunication with UEs depending on the network in which it is deployed,and may be alternatively referred to as an access point (AP), a networknode, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), aNew Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A basestation may be used primarily to support wireless access by UEs,including supporting data, voice, and/or signaling connections for thesupported UEs. In some systems a base station may provide purely edgenode signaling functions while in other systems it may provideadditional control and/or network management functions. A communicationlink through which UEs can send signals to a base station is called anuplink (UL) channel (e.g., a reverse traffic channel, a reverse controlchannel, an access channel, etc.). A communication link through whichthe base station can send signals to UEs is called a downlink (DL) orforward link channel (e.g., a paging channel, a control channel, abroadcast channel, a forward traffic channel, etc.). As used herein theterm traffic channel (TCH) can refer to either an uplink/reverse ordownlink/forward traffic channel.

The term “base station” may refer to a single physicaltransmission-reception point (TRP) or to multiple physical TRPs that mayor may not be co-located. For example, where the term “base station”refers to a single physical TRP, the physical TRP may be an antenna ofthe base station corresponding to a cell (or several cell sectors) ofthe base station. Where the term “base station” refers to multipleco-located physical TRPs, the physical TRPs may be an array of antennas(e.g., as in a multiple-input multiple-output (MIMO) system or where thebase station employs beamforming) of the base station. Where the term“base station” refers to multiple non-co-located physical TRPs, thephysical TRPs may be a distributed antenna system (DAS) (a network ofspatially separated antennas connected to a common source via atransport medium) or a remote radio head (RRH) (a remote base stationconnected to a serving base station). Alternatively, the non-co-locatedphysical TRPs may be the serving base station receiving the measurementreport from the UE and a neighbor base station whose reference radiofrequency (RF) signals the UE is measuring. Because a TRP is the pointfrom which a base station transmits and receives wireless signals, asused herein, references to transmission from or reception at a basestation are to be understood as referring to a particular TRP of thebase station.

In some implementations that support positioning of UEs, a base stationmay not support wireless access by UEs (e.g., may not support data,voice, and/or signaling connections for UEs), but may instead transmitreference signals to UEs to be measured by the UEs, and/or may receiveand measure signals transmitted by the UEs. Such a base station may bereferred to as a positioning beacon (e.g., when transmitting signals toUEs) and/or as a location measurement unit (e.g., when receiving andmeasuring signals from UEs).

An “RF signal” comprises an electromagnetic wave of a given frequencythat transports information through the space between a transmitter anda receiver. As used herein, a transmitter may transmit a single “RFsignal” or multiple “RF signals” to a receiver. However, the receivermay receive multiple “RF signals” corresponding to each transmitted RFsignal due to the propagation characteristics of RF signals throughmultipath channels. The same transmitted RF signal on different pathsbetween the transmitter and receiver may be referred to as a “multipath”RF signal. As used herein, an RF signal may also be referred to as a“wireless signal” or simply a “signal” where it is clear from thecontext that the term “signal” refers to a wireless signal or an RFsignal.

FIG. 1 illustrates an example wireless communications system 100,according to aspects of the disclosure. The wireless communicationssystem 100 (which may also be referred to as a wireless wide areanetwork (WWAN)) may include various base stations 102 (labeled “BS”) andvarious UEs 104. The base stations 102 may include macro cell basestations (high power cellular base stations) and/or small cell basestations (low power cellular base stations). In an aspect, the macrocell base stations may include eNBs and/or ng-eNBs where the wirelesscommunications system 100 corresponds to an LTE network, or gNBs wherethe wireless communications system 100 corresponds to a NR network, or acombination of both, and the small cell base stations may includefemtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC))through backhaul links 122, and through the core network 170 to one ormore location servers 172 (e.g., a location management function (LMF) ora secure user plane location (SUPL) location platform (SLP)). Thelocation server(s) 172 may be part of core network 170 or may beexternal to core network 170. In addition to other functions, the basestations 102 may perform functions that relate to one or more oftransferring user data, radio channel ciphering and deciphering,integrity protection, header compression, mobility control functions(e.g., handover, dual connectivity), inter-cell interferencecoordination, connection setup and release, load balancing, distributionfor non-access stratum (NAS) messages, NAS node selection,synchronization, RAN sharing, multimedia broadcast multicast service(MBMS), subscriber and equipment trace, RAN information management(RIM), paging, positioning, and delivery of warning messages. The basestations 102 may communicate with each other directly or indirectly(e.g., through the EPC/5GC) over backhaul links 134, which may be wiredor wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each geographic coverage area110. A “cell” is a logical communication entity used for communicationwith a base station (e.g., over some frequency resource, referred to asa carrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCI), an enhanced cell identifier (ECI), a virtual cell identifier(VCI), a cell global identifier (CGI), etc.) for distinguishing cellsoperating via the same or a different carrier frequency. In some cases,different cells may be configured according to different protocol types(e.g., machine-type communication (MTC), narrowband IoT (NB-IoT),enhanced mobile broadband (eMBB), or others) that may provide access fordifferent types of UEs. Because a cell is supported by a specific basestation, the term “cell” may refer to either or both of the logicalcommunication entity and the base station that supports it, depending onthe context. In addition, because a TRP is typically the physicaltransmission point of a cell, the terms “cell” and “TRP” may be usedinterchangeably. In some cases, the term “cell” may also refer to ageographic coverage area of a base station (e.g., a sector), insofar asa carrier frequency can be detected and used for communication withinsome portion of geographic coverage areas 110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell basestation 102′ (labeled “SC” for “small cell”) may have a geographiccoverage area 110′ that substantially overlaps with the geographiccoverage area 110 of one or more macro cell base stations 102. A networkthat includes both small cell and macro cell base stations may be knownas a heterogeneous network. A heterogeneous network may also includehome eNBs (HeNBs), which may provide service to a restricted group knownas a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs104 may include uplink (also referred to as reverse link) transmissionsfrom a UE 104 to a base station 102 and/or downlink (DL) (also referredto as forward link) transmissions from a base station 102 to a UE 104.The communication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to downlink anduplink (e.g., more or less carriers may be allocated for downlink thanfor uplink).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) or listen before talk (LBT) procedureprior to communicating in order to determine whether the channel isavailable.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or NRtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. NR in unlicensed spectrum maybe referred to as NR-U. LTE in an unlicensed spectrum may be referred toas LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a millimeterwave (mmW) base station 180 that may operate in mmW frequencies and/ornear mmW frequencies in communication with a UE 182. Extremely highfrequency (EHF) is part of the RF in the electromagnetic spectrum. EHFhas a range of 30 GHz to 300 GHz and a wavelength between 1 millimeterand 10 millimeters. Radio waves in this band may be referred to as amillimeter wave. Near mmW may extend down to a frequency of 3 GHz with awavelength of 100 millimeters. The super high frequency (SHF) bandextends between 3 GHz and 30 GHz, also referred to as centimeter wave.Communications using the mmW/near mmW radio frequency band have highpath loss and a relatively short range. The mmW base station 180 and theUE 182 may utilize beamforming (transmit and/or receive) over a mmWcommunication link 184 to compensate for the extremely high path lossand short range. Further, it will be appreciated that in alternativeconfigurations, one or more base stations 102 may also transmit usingmmW or near mmW and beamforming. Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

Transmit beams may be quasi-co-located, meaning that they appear to thereceiver (e.g., a UE) as having the same parameters, regardless ofwhether or not the transmitting antennas of the network node themselvesare physically co-located. In NR, there are four types ofquasi-co-location (QCL) relations. Specifically, a QCL relation of agiven type means that certain parameters about a second reference RFsignal on a second beam can be derived from information about a sourcereference RF signal on a source beam. Thus, if the source reference RFsignal is QCL Type A, the receiver can use the source reference RFsignal to estimate the Doppler shift, Doppler spread, average delay, anddelay spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type B, the receivercan use the source reference RF signal to estimate the Doppler shift andDoppler spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type C, the receivercan use the source reference RF signal to estimate the Doppler shift andaverage delay of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type D, the receivercan use the source reference RF signal to estimate the spatial receiveparameter of a second reference RF signal transmitted on the samechannel.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

Transmit and receive beams may be spatially related. A spatial relationmeans that parameters for a second beam (e.g., a transmit or receivebeam) for a second reference signal can be derived from informationabout a first beam (e.g., a receive beam or a transmit beam) for a firstreference signal. For example, a UE may use a particular receive beam toreceive a reference downlink reference signal (e.g., synchronizationsignal block (SSB)) from a base station. The UE can then form a transmitbeam for sending an uplink reference signal (e.g., sounding referencesignal (SRS)) to that base station based on the parameters of thereceive beam.

Note that a “downlink” beam may be either a transmit beam or a receivebeam, depending on the entity forming it. For example, if a base stationis forming the downlink beam to transmit a reference signal to a UE, thedownlink beam is a transmit beam. If the UE is forming the downlinkbeam, however, it is a receive beam to receive the downlink referencesignal. Similarly, an “uplink” beam may be either a transmit beam or areceive beam, depending on the entity forming it. For example, if a basestation is forming the uplink beam, it is an uplink receive beam, and ifa UE is forming the uplink beam, it is an uplink transmit beam.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102/180, UEs 104/182) operate is divided into multiplefrequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). mmWfrequency bands generally include the FR2, FR3, and FR4 frequencyranges. As such, the terms “mmW” and “FR2” or “FR3” or “FR4” maygenerally be used interchangeably.

In a multi-carrier system, such as 5G, one of the carrier frequencies isreferred to as the “primary carrier” or “anchor carrier” or “primaryserving cell” or “PCell,” and the remaining carrier frequencies arereferred to as “secondary carriers” or “secondary serving cells” or“SCells.” In carrier aggregation, the anchor carrier is the carrieroperating on the primary frequency (e.g., FR1) utilized by a UE 104/182and the cell in which the UE 104/182 either performs the initial radioresource control (RRC) connection establishment procedure or initiatesthe RRC connection re-establishment procedure. The primary carriercarries all common and UE-specific control channels, and may be acarrier in a licensed frequency (however, this is not always the case).A secondary carrier is a carrier operating on a second frequency (e.g.,FR2) that may be configured once the RRC connection is establishedbetween the UE 104 and the anchor carrier and that may be used toprovide additional radio resources. In some cases, the secondary carriermay be a carrier in an unlicensed frequency. The secondary carrier maycontain only necessary signaling information and signals, for example,those that are UE-specific may not be present in the secondary carrier,since both primary uplink and downlink carriers are typicallyUE-specific. This means that different UEs 104/182 in a cell may havedifferent downlink primary carriers. The same is true for the uplinkprimary carriers. The network is able to change the primary carrier ofany UE 104/182 at any time. This is done, for example, to balance theload on different carriers. Because a “serving cell” (whether a PCell oran SCell) corresponds to a carrier frequency/component carrier overwhich some base station is communicating, the term “cell,” “servingcell,” “component carrier,” “carrier frequency,” and the like can beused interchangeably.

For example, still referring to FIG. 1, one of the frequencies utilizedby the macro cell base stations 102 may be an anchor carrier (or“PCell”) and other frequencies utilized by the macro cell base stations102 and/or the mmW base station 180 may be secondary carriers(“SCells”). The simultaneous transmission and/or reception of multiplecarriers enables the UE 104/182 to significantly increase its datatransmission and/or reception rates. For example, two 20 MHz aggregatedcarriers in a multi-carrier system would theoretically lead to atwo-fold increase in data rate (i.e., 40 MHz), compared to that attainedby a single 20 MHz carrier.

The wireless communications system 100 may further include a UE 164 thatmay communicate with a macro cell base station 102 over a communicationlink 120 and/or the mmW base station 180 over a mmW communication link184. For example, the macro cell base station 102 may support a PCelland one or more SCells for the UE 164 and the mmW base station 180 maysupport one or more SCells for the UE 164.

In the example of FIG. 1, one or more Earth orbiting satellitepositioning system (SPS) space vehicles (SVs) 112 (e.g., satellites) maybe used as an independent source of location information for any of theillustrated UEs (shown in FIG. 1 as a single UE 104 for simplicity). AUE 104 may include one or more dedicated SPS receivers specificallydesigned to receive SPS signals 124 for deriving geo locationinformation from the SVs 112. An SPS typically includes a system oftransmitters (e.g., SVs 112) positioned to enable receivers (e.g., UEs104) to determine their location on or above the Earth based, at leastin part, on signals (e.g., SPS signals 124) received from thetransmitters. Such a transmitter typically transmits a signal markedwith a repeating pseudo-random noise (PN) code of a set number of chips.While typically located in SVs 112, transmitters may sometimes belocated on ground-based control stations, base stations 102, and/orother UEs 104.

The use of SPS signals 124 can be augmented by various satellite-basedaugmentation systems (SBAS) that may be associated with or otherwiseenabled for use with one or more global and/or regional navigationsatellite systems. For example an SBAS may include an augmentationsystem(s) that provides integrity information, differential corrections,etc., such as the Wide Area Augmentation System (WAAS), the EuropeanGeostationary Navigation Overlay Service (EGNOS), the Multi-functionalSatellite Augmentation System (MSAS), the Global Positioning System(GPS) Aided Geo Augmented Navigation or GPS and Geo Augmented Navigationsystem (GAGAN), and/or the like. Thus, as used herein, an SPS mayinclude any combination of one or more global and/or regional navigationsatellite systems and/or augmentation systems, and SPS signals 124 mayinclude SPS, SPS-like, and/or other signals associated with such one ormore SPS.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links (referred to as “sidelinks”). In the example ofFIG. 1, UE 190 has a D2D P2P link 192 with one of the UEs 104 connectedto one of the base stations 102 (e.g., through which UE 190 mayindirectly obtain cellular connectivity) and a D2D P2P link 194 withWLAN STA 152 connected to the WLAN AP 150 (through which UE 190 mayindirectly obtain WLAN-based Internet connectivity). In an example, theD2D P2P links 192 and 194 may be supported with any well-known D2D RAT,such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

FIG. 2A illustrates an example wireless network structure 200. Forexample, a 5GC 210 (also referred to as a Next Generation Core (NGC))can be viewed functionally as control plane (C-plane) functions 214(e.g., UE registration, authentication, network access, gatewayselection, etc.) and user plane (U-plane) functions 212, (e.g., UEgateway function, access to data networks, IP routing, etc.) whichoperate cooperatively to form the core network. User plane interface(NG-U) 213 and control plane interface (NG-C) 215 connect the gNB 222 tothe 5GC 210 and specifically to the user plane functions 212 and controlplane functions 214, respectively. In an additional configuration, anng-eNB 224 may also be connected to the 5GC 210 via NG-C 215 to thecontrol plane functions 214 and NG-U 213 to user plane functions 212.Further, ng-eNB 224 may directly communicate with gNB 222 via a backhaulconnection 223. In some configurations, a Next Generation RAN (NG-RAN)220 may have one or more gNBs 222, while other configurations includeone or more of both ng-eNBs 224 and gNBs 222. Either (or both) gNB 222or ng-eNB 224 may communicate with one or more UEs 204 (e.g., any of theUEs described herein).

Another optional aspect may include a location server 230, which may bein communication with the 5GC 210 to provide location assistance forUE(s) 204. The location server 230 can be implemented as a plurality ofseparate servers (e.g., physically separate servers, different softwaremodules on a single server, different software modules spread acrossmultiple physical servers, etc.), or alternately may each correspond toa single server. The location server 230 can be configured to supportone or more location services for UEs 204 that can connect to thelocation server 230 via the core network, 5GC 210, and/or via theInternet (not illustrated). Further, the location server 230 may beintegrated into a component of the core network, or alternatively may beexternal to the core network (e.g., a third party server, such as anoriginal equipment manufacturer (OEM) server or service server).

FIG. 2B illustrates another example wireless network structure 250. A5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewedfunctionally as control plane functions, provided by an access andmobility management function (AMF) 264, and user plane functions,provided by a user plane function (UPF) 262, which operate cooperativelyto form the core network (i.e., 5GC 260). The functions of the AMF 264include registration management, connection management, reachabilitymanagement, mobility management, lawful interception, transport forsession management (SM) messages between one or more UEs 204 (e.g., anyof the UEs described herein) and a session management function (SMF)266, transparent proxy services for routing SM messages, accessauthentication and access authorization, transport for short messageservice (SMS) messages between the UE 204 and the short message servicefunction (SMSF) (not shown), and security anchor functionality (SEAF).The AMF 264 also interacts with an authentication server function (AUSF)(not shown) and the UE 204, and receives the intermediate key that wasestablished as a result of the UE 204 authentication process. In thecase of authentication based on a UMTS (universal mobiletelecommunications system) subscriber identity module (USIM), the AMF264 retrieves the security material from the AUSF. The functions of theAMF 264 also include security context management (SCM). The SCM receivesa key from the SEAF that it uses to derive access-network specific keys.The functionality of the AMF 264 also includes location servicesmanagement for regulatory services, transport for location servicesmessages between the UE 204 and a location management function (LMF) 270(which acts as a location server 230), transport for location servicesmessages between the NG-RAN 220 and the LMF 270, evolved packet system(EPS) bearer identifier allocation for interworking with the EPS, and UE204 mobility event notification. In addition, the AMF 264 also supportsfunctionalities for non-3GPP (Third Generation Partnership Project)access networks.

Functions of the UPF 262 include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to a data network(not shown), providing packet routing and forwarding, packet inspection,user plane policy rule enforcement (e.g., gating, redirection, trafficsteering), lawful interception (user plane collection), traffic usagereporting, quality of service (QoS) handling for the user plane (e.g.,uplink/downlink rate enforcement, reflective QoS marking in thedownlink), uplink traffic verification (service data flow (SDF) to QoSflow mapping), transport level packet marking in the uplink anddownlink, downlink packet buffering and downlink data notificationtriggering, and sending and forwarding of one or more “end markers” tothe source RAN node. The UPF 262 may also support transfer of locationservices messages over a user plane between the UE 204 and a locationserver, such as an SLP 272.

The functions of the SMF 266 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF262 to route traffic to the proper destination, control of part ofpolicy enforcement and QoS, and downlink data notification. Theinterface over which the SMF 266 communicates with the AMF 264 isreferred to as the N11 interface.

Another optional aspect may include an LMF 270, which may be incommunication with the 5GC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, 5GC 260, and/or via the Internet (not illustrated). The SLP 272may support similar functions to the LMF 270, but whereas the LMF 270may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a controlplane (e.g., using interfaces and protocols intended to convey signalingmessages and not voice or data), the SLP 272 may communicate with UEs204 and external clients (not shown in FIG. 2B) over a user plane (e.g.,using protocols intended to carry voice and/or data like thetransmission control protocol (TCP) and/or IP).

User plane interface 263 and control plane interface 265 connect the 5GC260, and specifically the UPF 262 and AMF 264, respectively, to one ormore gNBs 222 and/or ng-eNBs 224 in the NG-RAN 220. The interfacebetween gNB(s) 222 and/or ng-eNB(s) 224 and the AMF 264 is referred toas the “N2” interface, and the interface between gNB(s) 222 and/orng-eNB(s) 224 and the UPF 262 is referred to as the “N3” interface. ThegNB(s) 222 and/or ng-eNB(s) 224 of the NG-RAN 220 may communicatedirectly with each other via backhaul connections 223, referred to asthe “Xn-C” interface. One or more of gNBs 222 and/or ng-eNBs 224 maycommunicate with one or more UEs 204 over a wireless interface, referredto as the “Uu” interface.

The functionality of a gNB 222 is divided between a gNB central unit(gNB-CU) 226 and one or more gNB distributed units (gNB-DUs) 228. Theinterface 232 between the gNB-CU 226 and the one or more gNB-DUs 228 isreferred to as the “F1” interface. A gNB-CU 226 is a logical node thatincludes the base station functions of transferring user data, mobilitycontrol, radio access network sharing, positioning, session management,and the like, except for those functions allocated exclusively to thegNB-DU(s) 228. More specifically, the gNB-CU 226 hosts the radioresource control (RRC), service data adaptation protocol (SDAP), andpacket data convergence protocol (PDCP) protocols of the gNB 222. AgNB-DU 228 is a logical node that hosts the radio link control (RLC),medium access control (MAC), and physical (PHY) layers of the gNB 222.Its operation is controlled by the gNB-CU 226. One gNB-DU 228 cansupport one or more cells, and one cell is supported by only one gNB-DU228. Thus, a UE 204 communicates with the gNB-CU 226 via the RRC, SDAP,and PDCP layers and with a gNB-DU 228 via the RLC, MAC, and PHY layers.

FIGS. 3A, 3B, and 3C illustrate several example components (representedby corresponding blocks) that may be incorporated into a UE 302 (whichmay correspond to any of the UEs described herein), a base station 304(which may correspond to any of the base stations described herein), anda network entity 306 (which may correspond to or embody any of thenetwork functions described herein, including the location server 230and the LMF 270, or alternatively may be independent from the NG-RAN 220and/or 5GC 210/260 infrastructure depicted in FIGS. 2A and 2B, such as aprivate network) to support the file transmission operations as taughtherein. It will be appreciated that these components may be implementedin different types of apparatuses in different implementations (e.g., inan ASIC, in a system-on-chip (SoC), etc.). The illustrated componentsmay also be incorporated into other apparatuses in a communicationsystem. For example, other apparatuses in a system may includecomponents similar to those described to provide similar functionality.Also, a given apparatus may contain one or more of the components. Forexample, an apparatus may include multiple transceiver components thatenable the apparatus to operate on multiple carriers and/or communicatevia different technologies.

The UE 302 and the base station 304 each include at least one wirelesswide area network (WWAN) transceiver 310 and 350, respectively,providing means for communicating (e.g., means for transmitting, meansfor receiving, means for measuring, means for tuning, means forrefraining from transmitting, etc.) via one or more wirelesscommunication networks (not shown), such as an NR network, an LTEnetwork, a GSM network, and/or the like. The WWAN transceivers 310 and350 may be connected to one or more antennas 316 and 356, respectively,for communicating with other network nodes, such as other UEs, accesspoints, base stations (e.g., eNBs, gNBs), etc., via at least onedesignated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communicationmedium of interest (e.g., some set of time/frequency resources in aparticular frequency spectrum). The WWAN transceivers 310 and 350 may bevariously configured for transmitting and encoding signals 318 and 358(e.g., messages, indications, information, and so on), respectively,and, conversely, for receiving and decoding signals 318 and 358 (e.g.,messages, indications, information, pilots, and so on), respectively, inaccordance with the designated RAT. Specifically, the WWAN transceivers310 and 350 include one or more transmitters 314 and 354, respectively,for transmitting and encoding signals 318 and 358, respectively, and oneor more receivers 312 and 352, respectively, for receiving and decodingsignals 318 and 358, respectively.

The UE 302 and the base station 304 each also include, at least in somecases, at least one short-range wireless transceiver 320 and 360,respectively. The short-range wireless transceivers 320 and 360 may beconnected to one or more antennas 326 and 366, respectively, and providemeans for communicating (e.g., means for transmitting, means forreceiving, means for measuring, means for tuning, means for refrainingfrom transmitting, etc.) with other network nodes, such as other UEs,access points, base stations, etc., via at least one designated RAT(e.g., WiFi, LTE-D, Bluetooth®, Zigbee®, Z-Wave®, PC5, dedicatedshort-range communications (DSRC), wireless access for vehicularenvironments (WAVE), near-field communication (NFC), etc.) over awireless communication medium of interest. The short-range wirelesstransceivers 320 and 360 may be variously configured for transmittingand encoding signals 328 and 368 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 328 and 368 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the short-range wireless transceivers 320and 360 include one or more transmitters 324 and 364, respectively, fortransmitting and encoding signals 328 and 368, respectively, and one ormore receivers 322 and 362, respectively, for receiving and decodingsignals 328 and 368, respectively. As specific examples, the short-rangewireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth®transceivers, Zigbee® and/or Z-Wave® transceivers, NFC transceivers, orvehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X)transceivers.

Transceiver circuitry including at least one transmitter and at leastone receiver may comprise an integrated device (e.g., embodied as atransmitter circuit and a receiver circuit of a single communicationdevice) in some implementations, may comprise a separate transmitterdevice and a separate receiver device in some implementations, or may beembodied in other ways in other implementations. In an aspect, atransmitter may include or be coupled to a plurality of antennas (e.g.,antennas 316, 326, 356, 366), such as an antenna array, that permits therespective apparatus to perform transmit “beamforming,” as describedherein. Similarly, a receiver may include or be coupled to a pluralityof antennas (e.g., antennas 316, 326, 356, 366), such as an antennaarray, that permits the respective apparatus to perform receivebeamforming, as described herein. In an aspect, the transmitter andreceiver may share the same plurality of antennas (e.g., antennas 316,326, 356, 366), such that the respective apparatus can only receive ortransmit at a given time, not both at the same time. A wirelesscommunication device (e.g., one or both of the transceivers 310 and 320and/or 350 and 360) of the UE 302 and/or the base station 304 may alsocomprise a network listen module (NLM) or the like for performingvarious measurements.

The UE 302 and the base station 304 also include, at least in somecases, satellite positioning systems (SPS) receivers 330 and 370. TheSPS receivers 330 and 370 may be connected to one or more antennas 336and 376, respectively, and may provide means for receiving and/ormeasuring SPS signals 338 and 378, respectively, such as globalpositioning system (GPS) signals, global navigation satellite system(GLONASS) signals, Galileo signals, Beidou signals, Indian RegionalNavigation Satellite System (NAVIC), Quasi-Zenith Satellite System(QZSS), etc. The SPS receivers 330 and 370 may comprise any suitablehardware and/or software for receiving and processing SPS signals 338and 378, respectively. The SPS receivers 330 and 370 request informationand operations as appropriate from the other systems, and performscalculations necessary to determine positions of the UE 302 and the basestation 304 using measurements obtained by any suitable SPS algorithm.

The base station 304 and the network entity 306 each include at leastone network interface 380 and 390, respectively, providing means forcommunicating (e.g., means for transmitting, means for receiving, etc.)with other network entities. For example, the network interfaces 380 and390 (e.g., one or more network access ports) may be configured tocommunicate with one or more network entities via a wire-based orwireless backhaul connection. In some aspects, the network interfaces380 and 390 may be implemented as transceivers configured to supportwire-based or wireless signal communication. This communication mayinvolve, for example, sending and receiving messages, parameters, and/orother types of information.

In an aspect, the at least one WWAN transceiver 310 and/or the at leastone short-range wireless transceiver 320 may form a (wireless)communication interface of the UE 302. Similarly, the at least one WWANtransceiver 350, the at least one short-range wireless transceiver 360,and/or the at least one network interface 380 may form a (wireless)communication interface of the base station 304. Likewise, the at leastone network interface 390 may form a (wireless) communication interfaceof the network entity 306. The various wireless transceivers (e.g.,transceivers 310, 320, 350, and 360) and wired transceivers (e.g.,network interfaces 380 and 390) may generally be characterized as atleast one transceiver, or alternatively, as at least one communicationinterface. As such, whether a particular transceiver or communicationinterface relates to a wired or wireless transceiver or communicationinterface, respectively, may be inferred from the type of communicationperformed (e.g., a backhaul communication between network devices orservers will generally relate to signaling via at least one wiredtransceiver).

The UE 302, the base station 304, and the network entity 306 alsoinclude other components that may be used in conjunction with theoperations as disclosed herein. The UE 302, the base station 304, andthe network entity 306 include at least one processor 332, 384, and 394,respectively, for providing functionality relating to, for example,wireless communication, and for providing other processingfunctionality. The processors 332, 384, and 394 may therefore providemeans for processing, such as means for determining, means forcalculating, means for receiving, means for transmitting, means forindicating, etc. In an aspect, the processors 332, 384, and 394 mayinclude, for example, at least one general purpose processor, multi-coreprocessor, central processing unit (CPU), ASIC, digital signal processor(DSP), field programmable gate array (FPGA), other programmable logicdevices or processing circuitry, or various combinations thereof.

The UE 302, the base station 304, and the network entity 306 includememory circuitry implementing memory components 340, 386, and 396 (e.g.,each including a memory device), respectively, for maintaininginformation (e.g., information indicative of reserved resources,thresholds, parameters, and so on). The memory components 340, 386, and396 may therefore provide means for storing, means for retrieving, meansfor maintaining, etc. In some cases, the UE 302, the base station 304,and the network entity 306 may include positioning components 342, 388,and 398, respectively. The positioning components 342, 388, and 398 maybe hardware circuits that are part of or coupled to the processors 332,384, and 394, respectively, that, when executed, cause the UE 302, thebase station 304, and the network entity 306 to perform thefunctionality described herein. In other aspects, the positioningcomponents 342, 388, and 398 may be external to the processors 332, 384,and 394 (e.g., part of a modem processing system, integrated withanother processing system, etc.). Alternatively, the positioningcomponents 342, 388, and 398 may be memory modules stored in the memorycomponents 340, 386, and 396, respectively, that, when executed by theprocessors 332, 384, and 394 (or a modem processing system, anotherprocessing system, etc.), cause the UE 302, the base station 304, andthe network entity 306 to perform the functionality described herein.FIG. 3A illustrates possible locations of the positioning component 342,which may be, for example, part of the at least one WWAN transceiver310, the memory component 340, the at least one processor 332, or anycombination thereof, or may be a standalone component. FIG. 3Billustrates possible locations of the positioning component 388, whichmay be, for example, part of the at least one WWAN transceiver 350, thememory component 386, the at least one processor 384, or any combinationthereof, or may be a standalone component. FIG. 3C illustrates possiblelocations of the positioning component 398, which may be, for example,part of the at least one network interface 390, the memory component396, the at least one processor 394, or any combination thereof, or maybe a standalone component.

The UE 302 may include one or more sensors 344 coupled to the at leastone processor 332 to provide means for sensing or detecting movementand/or orientation information that is independent of motion dataderived from signals received by the at least one WWAN transceiver 310,the at least one short-range wireless transceiver 320, and/or the SPSreceiver 330. By way of example, the sensor(s) 344 may include anaccelerometer (e.g., a micro-electrical mechanical systems (MEMS)device), a gyroscope, a geomagnetic sensor (e.g., a compass), analtimeter (e.g., a barometric pressure altimeter), and/or any other typeof movement detection sensor. Moreover, the sensor(s) 344 may include aplurality of different types of devices and combine their outputs inorder to provide motion information. For example, the sensor(s) 344 mayuse a combination of a multi-axis accelerometer and orientation sensorsto provide the ability to compute positions in two-dimensional (2D)and/or three-dimensional (3D) coordinate systems.

In addition, the UE 302 includes a user interface 346 providing meansfor providing indications (e.g., audible and/or visual indications) to auser and/or for receiving user input (e.g., upon user actuation of asensing device such a keypad, a touch screen, a microphone, and so on).Although not shown, the base station 304 and the network entity 306 mayalso include user interfaces.

Referring to the at least one processor 384 in more detail, in thedownlink, IP packets from the network entity 306 may be provided to theat least one processor 384. The at least one processor 384 may implementfunctionality for an RRC layer, a packet data convergence protocol(PDCP) layer, a radio link control (RLC) layer, and a medium accesscontrol (MAC) layer. The at least one processor 384 may provide RRClayer functionality associated with broadcasting of system information(e.g., master information block (MIB), system information blocks(SIBs)), RRC connection control (e.g., RRC connection paging, RRCconnection establishment, RRC connection modification, and RRCconnection release), inter-RAT mobility, and measurement configurationfor UE measurement reporting; PDCP layer functionality associated withheader compression/decompression, security (ciphering, deciphering,integrity protection, integrity verification), and handover supportfunctions; RLC layer functionality associated with the transfer of upperlayer PDUs, error correction through automatic repeat request (ARQ),concatenation, segmentation, and reassembly of RLC service data units(SDUs), re-segmentation of RLC data PDUs, and reordering of RLC dataPDUs; and MAC layer functionality associated with mapping betweenlogical channels and transport channels, scheduling informationreporting, error correction, priority handling, and logical channelprioritization.

The transmitter 354 and the receiver 352 may implement Layer-1 (L1)functionality associated with various signal processing functions.Layer-1, which includes a physical (PHY) layer, may include errordetection on the transport channels, forward error correction (FEC)coding/decoding of the transport channels, interleaving, rate matching,mapping onto physical channels, modulation/demodulation of physicalchannels, and MIMO antenna processing. The transmitter 354 handlesmapping to signal constellations based on various modulation schemes(e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an orthogonalfrequency division multiplexing (OFDM) subcarrier, multiplexed with areference signal (e.g., pilot) in the time and/or frequency domain, andthen combined together using an inverse fast Fourier transform (IFFT) toproduce a physical channel carrying a time domain OFDM symbol stream.The OFDM symbol stream is spatially precoded to produce multiple spatialstreams. Channel estimates from a channel estimator may be used todetermine the coding and modulation scheme, as well as for spatialprocessing. The channel estimate may be derived from a reference signaland/or channel condition feedback transmitted by the UE 302. Eachspatial stream may then be provided to one or more different antennas356. The transmitter 354 may modulate an RF carrier with a respectivespatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respectiveantenna(s) 316. The receiver 312 recovers information modulated onto anRF carrier and provides the information to the at least one processor332. The transmitter 314 and the receiver 312 implement Layer-1functionality associated with various signal processing functions. Thereceiver 312 may perform spatial processing on the information torecover any spatial streams destined for the UE 302. If multiple spatialstreams are destined for the UE 302, they may be combined by thereceiver 312 into a single OFDM symbol stream. The receiver 312 thenconverts the OFDM symbol stream from the time-domain to the frequencydomain using a fast Fourier transform (FFT). The frequency domain signalcomprises a separate OFDM symbol stream for each subcarrier of the OFDMsignal. The symbols on each subcarrier, and the reference signal, arerecovered and demodulated by determining the most likely signalconstellation points transmitted by the base station 304. These softdecisions may be based on channel estimates computed by a channelestimator. The soft decisions are then decoded and de-interleaved torecover the data and control signals that were originally transmitted bythe base station 304 on the physical channel. The data and controlsignals are then provided to the at least one processor 332, whichimplements Layer-3 (L3) and Layer-2 (L2) functionality.

In the uplink, the at least one processor 332 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, and control signal processing to recover IPpackets from the core network. The at least one processor 332 is alsoresponsible for error detection.

Similar to the functionality described in connection with the downlinktransmission by the base station 304, the at least one processor 332provides RRC layer functionality associated with system information(e.g., MIB, SIBs) acquisition, RRC connections, and measurementreporting; PDCP layer functionality associated with headercompression/decompression, and security (ciphering, deciphering,integrity protection, integrity verification); RLC layer functionalityassociated with the transfer of upper layer PDUs, error correctionthrough ARQ, concatenation, segmentation, and reassembly of RLC SDUs,re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, multiplexing of MAC SDUs onto transport blocks(TBs), demultiplexing of MAC SDUs from TBs, scheduling informationreporting, error correction through hybrid automatic repeat request(HARD), priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator from a referencesignal or feedback transmitted by the base station 304 may be used bythe transmitter 314 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the transmitter 314 may be provided to different antenna(s)316. The transmitter 314 may modulate an RF carrier with a respectivespatial stream for transmission.

The uplink transmission is processed at the base station 304 in a mannersimilar to that described in connection with the receiver function atthe UE 302. The receiver 352 receives a signal through its respectiveantenna(s) 356. The receiver 352 recovers information modulated onto anRF carrier and provides the information to the at least one processor384.

In the uplink, the at least one processor 384 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, control signal processing to recover IP packetsfrom the UE 302. IP packets from the at least one processor 384 may beprovided to the core network. The at least one processor 384 is alsoresponsible for error detection.

For convenience, the UE 302, the base station 304, and/or the networkentity 306 are shown in FIGS. 3A, 3B, and 3C as including variouscomponents that may be configured according to the various examplesdescribed herein. It will be appreciated, however, that the illustratedcomponents may have different functionality in different designs.

The various components of the UE 302, the base station 304, and thenetwork entity 306 may communicate with each other over data buses 334,382, and 392, respectively. In an aspect, the data buses 334, 382, and392 may form, or be part of, the communication interface of the UE 302,the base station 304, and the network entity 306, respectively. Forexample, where different logical entities are embodied in the samedevice (e.g., gNB and location server functionality incorporated intothe same base station 304), the data buses 334, 382, and 392 may providecommunication between them.

The components of FIGS. 3A, 3B, and 3C may be implemented in variousways. In some implementations, the components of FIGS. 3A, 3B, and 3Cmay be implemented in one or more circuits such as, for example, one ormore processors and/or one or more ASICs (which may include one or moreprocessors). Here, each circuit may use and/or incorporate at least onememory component for storing information or executable code used by thecircuit to provide this functionality. For example, some or all of thefunctionality represented by blocks 310 to 346 may be implemented byprocessor and memory component(s) of the UE 302 (e.g., by execution ofappropriate code and/or by appropriate configuration of processorcomponents). Similarly, some or all of the functionality represented byblocks 350 to 388 may be implemented by processor and memorycomponent(s) of the base station 304 (e.g., by execution of appropriatecode and/or by appropriate configuration of processor components). Also,some or all of the functionality represented by blocks 390 to 398 may beimplemented by processor and memory component(s) of the network entity306 (e.g., by execution of appropriate code and/or by appropriateconfiguration of processor components). For simplicity, variousoperations, acts, and/or functions are described herein as beingperformed “by a UE,” “by a base station,” “by a network entity,” etc.However, as will be appreciated, such operations, acts, and/or functionsmay actually be performed by specific components or combinations ofcomponents of the UE 302, base station 304, network entity 306, etc.,such as the processors 332, 384, 394, the transceivers 310, 320, 350,and 360, the memory components 340, 386, and 396, the positioningcomponents 342, 388, and 398, etc.

In some designs, the network entity 306 may be implemented as a corenetwork component. In other designs, the network entity 306 may bedistinct from a network operator or operation of the cellular networkinfrastructure (e.g., NG RAN 220 and/or 5GC 210/260). For example, thenetwork entity 306 may be a component of a private network that may beconfigured to communicate with the UE 302 via the base station 304 orindependently from the base station 304 (e.g., over a non-cellularcommunication link, such as WiFi).

NR supports a number of cellular network-based positioning technologies,including downlink-based, uplink-based, and downlink-and-uplink-basedpositioning methods. Downlink-based positioning methods include observedtime difference of arrival (OTDOA) in LTE, downlink time difference ofarrival (DL-TDOA) in NR, and downlink angle-of-departure (DL-AoD) in NR.In an OTDOA or DL-TDOA positioning procedure, a UE measures thedifferences between the times of arrival (ToAs) of reference signals(e.g., positioning reference signals (PRS)) received from pairs of basestations, referred to as reference signal time difference (RSTD) or timedifference of arrival (TDOA) measurements, and reports them to apositioning entity. More specifically, the UE receives the identifiers(IDs) of a reference base station (e.g., a serving base station) andmultiple non-reference base stations in assistance data. The UE thenmeasures the RSTD between the reference base station and each of thenon-reference base stations. Based on the known locations of theinvolved base stations and the RSTD measurements, the positioning entitycan estimate the UE's location.

For DL-AoD positioning, the positioning entity uses a beam report fromthe UE of received signal strength measurements of multiple downlinktransmit beams to determine the angle(s) between the UE and thetransmitting base station(s). The positioning entity can then estimatethe location of the UE based on the determined angle(s) and the knownlocation(s) of the transmitting base station(s).

Uplink-based positioning methods include uplink time difference ofarrival (UL-TDOA) and uplink angle-of-arrival (UL-AoA). UL-TDOA issimilar to DL-TDOA, but is based on uplink reference signals (e.g.,sounding reference signals (SRS)) transmitted by the UE. For UL-AoApositioning, one or more base stations measure the received signalstrength of one or more uplink reference signals (e.g., SRS) receivedfrom a UE on one or more uplink receive beams. The positioning entityuses the signal strength measurements and the angle(s) of the receivebeam(s) to determine the angle(s) between the UE and the basestation(s). Based on the determined angle(s) and the known location(s)of the base station(s), the positioning entity can then estimate thelocation of the UE.

Downlink-and-uplink-based positioning methods include enhanced cell-ID(E-CID) positioning and multi-round-trip-time (RTT) positioning (alsoreferred to as “multi-cell RTT”). In an RTT procedure, an initiator (abase station or a UE) transmits an RTT measurement signal (e.g., a PRSor SRS) to a responder (a UE or base station), which transmits an RTTresponse signal (e.g., an SRS or PRS) back to the initiator. The RTTresponse signal includes the difference between the ToA of the RTTmeasurement signal and the transmission time of the RTT response signal,referred to as the reception-to-transmission (Rx-Tx) time difference.The initiator calculates the difference between the transmission time ofthe RTT measurement signal and the ToA of the RTT response signal,referred to as the transmission-to-reception (Tx-Rx) time difference.The propagation time (also referred to as the “time of flight”) betweenthe initiator and the responder can be calculated from the Tx-Rx andRx-Tx time differences. Based on the propagation time and the knownspeed of light, the distance between the initiator and the responder canbe determined. For multi-RTT positioning, a UE performs an RTT procedurewith multiple base stations to enable its location to be determined(e.g., using multilateration) based on the known locations of the basestations. RTT and multi-RTT methods can be combined with otherpositioning techniques, such as UL-AoA and DL-AoD, to improve locationaccuracy.

The E-CID positioning method is based on radio resource management (RRM)measurements. In E-CID, the UE reports the serving cell ID, the timingadvance (TA), and the identifiers, estimated timing, and signal strengthof detected neighbor base stations. The location of the UE is thenestimated based on this information and the known locations of the basestation(s).

To assist positioning operations, a location server (e.g., locationserver 230, LMF 270, SLP 272) may provide assistance data to the UE. Forexample, the assistance data may include identifiers of the basestations (or the cells/TRPs of the base stations) from which to measurereference signals, the reference signal configuration parameters (e.g.,the number of consecutive positioning subframes, periodicity ofpositioning subframes, muting sequence, frequency hopping sequence,reference signal identifier, reference signal bandwidth, etc.), and/orother parameters applicable to the particular positioning method.Alternatively, the assistance data may originate directly from the basestations themselves (e.g., in periodically broadcasted overheadmessages, etc.). in some cases, the UE may be able to detect neighbornetwork nodes itself without the use of assistance data.

In the case of an OTDOA or DL-TDOA positioning procedure, the assistancedata may further include an expected RSTD value and an associateduncertainty, or search window, around the expected RSTD. In some cases,the value range of the expected RSTD may be +/−500 microseconds (μs). Insome cases, when any of the resources used for the positioningmeasurement are in FR1, the value range for the uncertainty of theexpected RSTD may be +/−32 μs. In other cases, when all of the resourcesused for the positioning measurement(s) are in FR2, the value range forthe uncertainty of the expected RSTD may be +/−8 μs.

A location estimate may be referred to by other names, such as aposition estimate, location, position, position fix, fix, or the like. Alocation estimate may be geodetic and comprise coordinates (e.g.,latitude, longitude, and possibly altitude) or may be civic and comprisea street address, postal address, or some other verbal description of alocation. A location estimate may further be defined relative to someother known location or defined in absolute terms (e.g., using latitude,longitude, and possibly altitude). A location estimate may include anexpected error or uncertainty (e.g., by including an area or volumewithin which the location is expected to be included with some specifiedor default level of confidence).

Various frame structures may be used to support downlink and uplinktransmissions between network nodes (e.g., base stations and UEs). FIG.4A is a diagram 400 illustrating an example of a downlink framestructure, according to aspects of the disclosure. FIG. 4B is a diagram430 illustrating an example of channels within the downlink framestructure, according to aspects of the disclosure. Other wirelesscommunications technologies may have different frame structures and/ordifferent channels.

LTE, and in some cases NR, utilizes OFDM on the downlink andsingle-carrier frequency division multiplexing (SC-FDM) on the uplink.Unlike LTE, however, NR has an option to use OFDM on the uplink as well.OFDM and SC-FDM partition the system bandwidth into multiple (K)orthogonal subcarriers, which are also commonly referred to as tones,bins, etc. Each subcarrier may be modulated with data. In general,modulation symbols are sent in the frequency domain with OFDM and in thetime domain with SC-FDM. The spacing between adjacent subcarriers may befixed, and the total number of subcarriers (K) may be dependent on thesystem bandwidth. For example, the spacing of the subcarriers may be 15kilohertz (kHz) and the minimum resource allocation (resource block) maybe 12 subcarriers (or 180 kHz). Consequently, the nominal FFT size maybe equal to 128, 256, 512, 1024, or 2048 for system bandwidth of 1.25,2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidthmay also be partitioned into subbands. For example, a subband may cover1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16subbands for system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz,respectively.

LTE supports a single numerology (subcarrier spacing (SCS), symbollength, etc.). In contrast, NR may support multiple numerologies (μ),for example, subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz(μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or greater may be available. Ineach subcarrier spacing, there are 14 symbols per slot. For 15 kHz SCS(μ=0), there is one slot per subframe, 10 slots per frame, the slotduration is 1 millisecond (ms), the symbol duration is 66.7 microseconds(μs), and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 50. For 30 kHz SCS (μ=1), there are two slots per subframe, 20slots per frame, the slot duration is 0.5 ms, the symbol duration is33.3 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 100. For 60 kHz SCS (μ=2), there are four slots per subframe, 40slots per frame, the slot duration is 0.25 ms, the symbol duration is16.7 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 200. For 120 kHz SCS (μ=3), there are eight slots per subframe,80 slots per frame, the slot duration is 0.125 ms, the symbol durationis 8.33 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 400. For 240 kHz SCS (μ=4), there are 16 slots per subframe,160 slots per frame, the slot duration is 0.0625 ms, the symbol durationis 4.17 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 800.

In the example of FIGS. 4A and 4B, a numerology of 15 kHz is used. Thus,in the time domain, a 10 ms frame is divided into 10 equally sizedsubframes of 1 ms each, and each subframe includes one time slot. InFIGS. 4A and 4B, time is represented horizontally (on the X axis) withtime increasing from left to right, while frequency is representedvertically (on the Y axis) with frequency increasing (or decreasing)from bottom to top.

A resource grid may be used to represent time slots, each time slotincluding one or more time-concurrent resource blocks (RBs) (alsoreferred to as physical RBs (PRBs)) in the frequency domain. Theresource grid is further divided into multiple resource elements (REs).An RE may correspond to one symbol length in the time domain and onesubcarrier in the frequency domain. In the numerology of FIGS. 4A and4B, for a normal cyclic prefix, an RB may contain 12 consecutivesubcarriers in the frequency domain and seven consecutive symbols in thetime domain, for a total of 84 REs. For an extended cyclic prefix, an RBmay contain 12 consecutive subcarriers in the frequency domain and sixconsecutive symbols in the time domain, for a total of 72 REs. Thenumber of bits carried by each RE depends on the modulation scheme.

Some of the REs carry downlink reference (pilot) signals (DL-RS). TheDL-RS may include positioning reference signals (PRS), trackingreference signals (TRS), phase tracking reference signals (TRS),cell-specific reference signals (CRS), channel state informationreference signals (CSI-RS), demodulation reference signals (DMRS),primary synchronization signals (PSS), secondary synchronization signals(SSS), synchronization signal blocks (SSBs), etc. FIG. 4A illustratesexample locations of REs carrying PRS (labeled “R”).

A collection of resource elements (REs) that are used for transmissionof PRS is referred to as a “PRS resource.” The collection of resourceelements can span multiple PRBs in the frequency domain and ‘N’ (such as1 or more) consecutive symbol(s) within a slot in the time domain. In agiven OFDM symbol in the time domain, a PRS resource occupiesconsecutive PRBs in the frequency domain.

The transmission of a PRS resource within a given PRB has a particularcomb size (also referred to as the “comb density”). A comb size ‘N’represents the subcarrier spacing (or frequency/tone spacing) withineach symbol of a PRS resource configuration. Specifically, for a combsize ‘N,’ PRS are transmitted in every Nth subcarrier of a symbol of aPRB. For example, for comb-4, for each symbol of the PRS resourceconfiguration, REs corresponding to every fourth subcarrier (such assubcarriers 0, 4, 8) are used to transmit PRS of the PRS resource.Currently, comb sizes of comb-2, comb-4, comb-6, and comb-12 aresupported for DL-PRS. FIG. 4A illustrates an example PRS resourceconfiguration for comb-6 (which spans six symbols). That is, thelocations of the shaded REs (labeled “R”) indicate a comb-6 PRS resourceconfiguration.

Currently, a DL-PRS resource may span 2, 4, 6, or 12 consecutive symbolswithin a slot with a fully frequency-domain staggered pattern. A DL-PRSresource can be configured in any higher layer configured downlink orflexible (FL) symbol of a slot. There may be a constant energy perresource element (EPRE) for all REs of a given DL-PRS resource. Thefollowing are the frequency offsets from symbol to symbol for comb sizes2, 4, 6, and 12 over 2, 4, 6, and 12 symbols. 2-symbol comb-2: {0, 1};4-symbol comb-2: {0, 1, 0, 1}; 6-symbol comb-2: {0, 1, 0, 1, 0, 1};12-symbol comb-2: {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1}; 4-symbol comb-4:{0, 2, 1, 3}; 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3};6-symbol comb-6: {0, 3, 1, 4, 2, 5}; 12-symbol comb-6: {0, 3, 1, 4, 2,5, 0, 3, 1, 4, 2, 5}; and 12-symbol comb-12: {0, 6, 3, 9, 1, 7, 4, 10,2, 8, 5, 11}.

A “PRS resource set” is a set of PRS resources used for the transmissionof PRS signals, where each PRS resource has a PRS resource ID. Inaddition, the PRS resources in a PRS resource set are associated withthe same TRP. A PRS resource set is identified by a PRS resource set IDand is associated with a particular TRP (identified by a TRP ID). Inaddition, the PRS resources in a PRS resource set have the sameperiodicity, a common muting pattern configuration, and the samerepetition factor (such as “PRS-ResourceRepetitionFactor”) across slots.The periodicity is the time from the first repetition of the first PRSresource of a first PRS instance to the same first repetition of thesame first PRS resource of the next PRS instance. The periodicity mayhave a length selected from 2{circumflex over ( )}μ*{4, 5, 8, 10, 16,20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, withμ=0, 1, 2, 3. The repetition factor may have a length selected from {1,2, 4, 6, 8, 16, 32} slots.

A PRS resource ID in a PRS resource set is associated with a single beam(or beam ID) transmitted from a single TRP (where a TRP may transmit oneor more beams). That is, each PRS resource of a PRS resource set may betransmitted on a different beam, and as such, a “PRS resource,” orsimply “resource,” also can be referred to as a “beam.” Note that thisdoes not have any implications on whether the TRPs and the beams onwhich PRS are transmitted are known to the UE.

A “PRS instance” or “PRS occasion” is one instance of a periodicallyrepeated time window (such as a group of one or more consecutive slots)where PRS are expected to be transmitted. A PRS occasion also may bereferred to as a “PRS positioning occasion,” a “PRS positioninginstance, a “positioning occasion,” “a positioning instance,” a“positioning repetition,” or simply an “occasion,” an “instance,” or a“repetition.”

A “positioning frequency layer” (also referred to simply as a “frequencylayer”) is a collection of one or more PRS resource sets across one ormore TRPs that have the same values for certain parameters.Specifically, the collection of PRS resource sets has the samesubcarrier spacing and cyclic prefix (CP) type (meaning all numerologiessupported for the PDSCH are also supported for PRS), the same Point A,the same value of the downlink PRS bandwidth, the same start PRB (andcenter frequency), and the same comb-size. The Point A parameter takesthe value of the parameter “ARFCN-ValueNR” (where “ARFCN” stands for“absolute radio-frequency channel number”) and is an identifier/codethat specifies a pair of physical radio channel used for transmissionand reception. The downlink PRS bandwidth may have a granularity of fourPRBs, with a minimum of 24 PRBs and a maximum of 272 PRBs. Currently, upto four frequency layers have been defined, and up to two PRS resourcesets may be configured per TRP per frequency layer.

The concept of a frequency layer is somewhat like the concept ofcomponent carriers and bandwidth parts (BWPs), but different in thatcomponent carriers and BWPs are used by one base station (or a macrocell base station and a small cell base station) to transmit datachannels, while frequency layers are used by several (usually three ormore) base stations to transmit PRS. A UE may indicate the number offrequency layers it can support when it sends the network itspositioning capabilities, such as during an LTE positioning protocol(LPP) session. For example, a UE may indicate whether it can support oneor four positioning frequency layers.

FIG. 4B illustrates an example of various channels within a downlinkslot of a radio frame. In NR, the channel bandwidth, or systembandwidth, is divided into multiple BWPs. A BWP is a contiguous set ofPRBs selected from a contiguous subset of the common RBs for a givennumerology on a given carrier. Generally, a maximum of four BWPs can bespecified in the downlink and uplink. That is, a UE can be configuredwith up to four BWPs on the downlink, and up to four BWPs on the uplink.Only one BWP (uplink or downlink) may be active at a given time, meaningthe UE may only receive or transmit over one BWP at a time. On thedownlink, the bandwidth of each BWP should be equal to or greater thanthe bandwidth of the SSB, but it may or may not contain the SSB.

Referring to FIG. 4B, a primary synchronization signal (PSS) is used bya UE to determine subframe/symbol timing and a physical layer identity.A secondary synchronization signal (SSS) is used by a UE to determine aphysical layer cell identity group number and radio frame timing. Basedon the physical layer identity and the physical layer cell identitygroup number, the UE can determine a PCI. Based on the PCI, the UE candetermine the locations of the aforementioned DL-RS. The physicalbroadcast channel (PBCH), which carries an MIB, may be logically groupedwith the PSS and SSS to form an SSB (also referred to as an SS/PBCH).The MIB provides a number of RBs in the downlink system bandwidth and asystem frame number (SFN). The physical downlink shared channel (PDSCH)carries user data, broadcast system information not transmitted throughthe PBCH, such as system information blocks (SIBs), and paging messages.

The physical downlink control channel (PDCCH) carries downlink controlinformation (DCI) within one or more control channel elements (CCEs),each CCE including one or more RE group (REG) bundles (which may spanmultiple symbols in the time domain), each REG bundle including one ormore REGs, each REG corresponding to 12 resource elements (one resourceblock) in the frequency domain and one OFDM symbol in the time domain.The set of physical resources used to carry the PDCCH/DCI is referred toin NR as the control resource set (CORESET). In NR, a PDCCH is confinedto a single CORESET and is transmitted with its own DMRS. This enablesUE-specific beamforming for the PDCCH.

In the example of FIG. 4B, there is one CORESET per BWP, and the CORESETspans three symbols (although it may be only one or two symbols) in thetime domain. Unlike LTE control channels, which occupy the entire systembandwidth, in NR, PDCCH channels are localized to a specific region inthe frequency domain (i.e., a CORESET). Thus, the frequency component ofthe PDCCH shown in FIG. 4B is illustrated as less than a single BWP inthe frequency domain. Note that although the illustrated CORESET iscontiguous in the frequency domain, it need not be. In addition, theCORESET may span less than three symbols in the time domain.

The DCI within the PDCCH carries information about uplink resourceallocation (persistent and non-persistent) and descriptions aboutdownlink data transmitted to the UE, referred to as uplink and downlinkgrants, respectively. More specifically, the DCI indicates the resourcesscheduled for the downlink data channel (e.g., PDSCH) and the uplinkdata channel (e.g., PUSCH). Multiple (e.g., up to eight) DCIs can beconfigured in the PDCCH, and these DCIs can have one of multipleformats. For example, there are different DCI formats for uplinkscheduling, for downlink scheduling, for uplink transmit power control(TPC), etc. A PDCCH may be transported by 1, 2, 4, 8, or 16 CCEs inorder to accommodate different DCI payload sizes or coding rates.

Note that the terms “positioning reference signal” and “PRS” generallyrefer to specific reference signals that are used for positioning in NRand LTE systems. However, as used herein, the terms “positioningreference signal” and “PRS” may also refer to any type of referencesignal that can be used for positioning, such as but not limited to, PRSas defined in LTE and NR, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB,SRS, UL-PRS, etc. In addition, the terms “positioning reference signal”and “PRS” may refer to downlink or uplink positioning reference signals,unless otherwise indicated by the context. If needed to furtherdistinguish the type of PRS, a downlink positioning reference signal maybe referred to as a “DL-PRS,” and an uplink positioning reference signal(e.g., an SRS-for-positioning, PTRS) may be referred to as an “UL-PRS.”In addition, for signals that may be transmitted in both the uplink anddownlink (e.g., DMRS, PTRS), the signals may be prepended with “UL” or“DL” to distinguish the direction. For example, “UL-DMRS” may bedifferentiated from “DL-DMRS.”

FIG. 5 is a diagram 500 of an example radio frequency (RF) signalprocessing procedure, according to various aspects of the disclosure. Inorder to identify the time of arrival (ToA) of an RF signal (e.g., apositioning reference signal (PRS)), the receiver (e.g., a UE) firstbuffers and then jointly processes all the resource elements (REs) onthe channel on which the transmitter (e.g., a base station) istransmitting the RF signal. The receiver then performs an inverseFourier transform (FFT) to convert the received RF signal to the timedomain. The conversion of the received RF signal to the time domain isreferred to as the estimation of the channel energy response (CER) orchannel impulse response (CIR). The CER shows the peaks on the channelover time, and the earliest “significant” peak should thereforecorrespond to the ToA of the RF signal. Generally, the receiver will usea noise-related quality threshold to filter out spurious local peaks,thereby presumably correctly identifying significant peaks on thechannel. For example, the receiver may choose a ToA estimate that is theearliest local maximum of the CER that is at least ‘X’ decibels (dB)higher than the median of the CER and a maximum ‘Y’ dB lower than themain peak on the channel.

Thus, with reference to FIG. 5, at a fast Fourier transform (FFT) stage510, a receiver (e.g., any of the UEs described herein)receives/measures and buffers a time-domain RF signal (e.g., a PRS) andconverts it to a frequency-domain signal. At a correlation stage 520,the receiver generates a frequency-domain channel impulse response fromthe frequency-domain signal based on a descrambling sequence. At aninverse fast Fourier transform (IFFT) stage 530, the receiver generatesa time-domain channel impulse response from the frequency-domain channelimpulse response output by the correlation stage 520. At an earliestpeak detection stage 540, the receiver generates a detection indicationand a ToA of the time-domain RF signal received at the FFT stage 510based on the time-domain channel impulse response received from the IFFTstage 530.

Where the receiver is a UE, the UE may receive the time-domain RF signalat one or more of antennas 316. The subsequent stages (i.e., FFT stage510, correlation stage 520, IFFT stage 530, earliest peak detectionstage 540) may be performed by the one or more receivers 312, the atleast one WWAN transceiver 310, and/or the at least one processor 332,depending on the hardware implementation of the UE. Similarly, where thereceiver is a base station, the base station may receive the time-domainRF signal at one or more of antennas 356. The subsequent stages may beperformed by the one or more receivers 352, the at least one WWANtransceiver 350, and/or the at least one processor 384, depending on thehardware implementation of the base station.

As will be appreciated from the above, a receiver needs some amount oftime to buffer and process an RF signal, such as a PRS. The amount oftime needed may depend on various factors, such as the capabilities ofthe receiver, the number of REs carrying the RF signal, the bandwidth ofthe RF signal, and the like.

Buffering is needed because the receiver receives the RF signal overtime (e.g., over one or more symbols, slots, subframes, etc.), but thenneeds to process the RF signal on a per slot, per subframe, etc. basis.For example, where a UE is measuring a DL-PRS resource (comprising somenumber of symbols within a slot) to determine the ToA of the PRSresource, the UE needs to buffer and then process at least all thesymbols of the slot that may contain PRS REs in order to determine theToA of the PRS resource. Thus, the receiver stores the received/measuredRF signal in a buffer as it is received in order to then process the RFsignal.

There are two separate capabilities for DL-PRS processing, one relatedto the number of PRS resources and one related to the number of PRSsymbols. These two capabilities are (1) a limit on the maximum number‘N1’ of DL-PRS resources a UE is expected to measure across all TRPs andfrequency layers within a measurement window of ‘T1’ ms, reported as alist of duplets {N1, T1}, and (2) a limit on the maximum number ofsymbols ‘N2’ containing PRS resources of maximum bandwidth that a UE isexpected to measure within a measurement window of ‘T2’ ms, reported asa list of duplets {N2, T2}.

The duration of DL-PRS symbols is given in units of milliseconds that aUE can process every ‘T’ ms, assuming that a 272 PRB allocation is a UEcapability. In addition, a limit on the maximum number of DL-PRSresources configured to the UE for all TRPs within a measurement windowis defined. This limit can be signalled as a UE capability.

A UE may report, in MHz, its DL-PRS processing capability for themaximum DL-PRS bandwidth. A UE is not expected to support a DL-PRSbandwidth that exceeds this reported DL-PRS bandwidth value. Inaddition, the UE signals its DL-PRS processing capability per band.Further, a UE's DL-PRS processing capability is defined for a singlepositioning frequency layer. A UE's DL-PRS processing capability isagnostic to the DL-PRS comb factor configuration.

If a UE is configured by higher layers (e.g., LTE positioning protocol(LPP)) to receive PRS symbols with a periodicity ‘P,’ the symbolduration ‘K’ (i.e., the number of symbols that the UE needs to bufferand process in order to measure the PRS) is calculated by:

$K = {\sum\limits_{s \in S}^{\;}K_{S}}$$K_{S} = {\frac{1}{2^{\mu}N_{symb}^{slot}}( {{{ceil}( {2^{\mu}N_{symb}^{slot}T_{S}^{end}} )} - {{floor}( {2^{\mu}N_{symb}^{slot}T_{S}^{start}} )}} )}$

where ‘S’ is the smallest set of consecutive slots within the PRSperiodicity in the positioning frequency layer that contains all PRSacross TRPs, μ is the numerology of the PRS resources in the positioningfrequency layer, N_(symb) ^(slot) is the number of symbols per slot, and[T_(S) ^(start), T_(S) ^(end)] is the smallest interval in millisecondswithin slot ‘s’ that covers the union of the potential PRS symbols fromall TRPs, where each potential PRS symbol is determined by theparameters “nr-DL-PRS-ExpectedRSTD” and“nr-DL-PRS-ExpectedRSTD-Uncertainty” and the PRS symbol occupancy withinslot ‘s.’

A “potential” PRS symbol is a time-domain duration during which a UEexpects a PRS to be received, as provided by the parameters“nr-DL-PRS-ExpectedRSTD” and “nr-DL-PRS-ExpectedRSTD-Uncertainty” andthe PRS symbol occupancy within slot ‘s.’ For example, if a two-symbolPRS is configured in symbols ‘3’ and ‘4’ (see, e.g., FIG. 4A) with an“nr-DL-PRS-ExpectedRSTD” of ‘0’ and an“nr-DL-PRS-ExpectedRSTD-Uncertainty” of 32 microseconds (μs) in 30 KhzSCS numerology, then the PRS may actually be received as early assymbols ‘2’ and ‘3’ or as late as symbols ‘4’ and ‘5,’ respectively (as32 μs is approximately one symbol duration in 30 KHz SCS). Therefore, inthis example, the potential PRS symbols are symbols ‘2’ to ‘5’ becausethis is the time domain region during which the UE expects to receivethe PRS based on the configuration and assistance data (i.e.,“nr-DL-PRS-ExpectedRSTD” and “nr-DL-PRS-ExpectedRSTD-Uncertainty”).

FIG. 6 is a diagram 600 illustrating an example of slot-based PRSprocessing, according to aspects of the disclosure. FIG. 6 illustratesthree consecutive slots 610 during which a UE expects to receive/measurePRS from a reference cell (or TRP) and a neighbor cell (or TRP). Eachblock illustrated in FIG. 6 represents a duration of symbols duringwhich the UE expects to receive the PRS from the respective cell. Thismay also be referred to as the expected PRS symbol occupancy within theslot 610. For the reference cell, the UE expects to receive PRS fromthat cell during block 612. Because of the uncertainty of when the UEmay receive PRS from a neighboring cell (as indicated by“nr-DL-PRS-ExpectedRSTD-Uncertainty”), the PRS from the neighboring cellare illustrated as two different blocks, with block 614 representing theearliest time period the UE expects to receive the PRS from theneighboring cell and block 616 representing the latest time period theUE expects to receive the PRS from the neighboring cell. As will beappreciated, the UE may receive PRS from the neighboring cell at anytime between the start of block 614 and the end of block 616.

Thus, in FIG. 6, the duration 620 of PRS symbols to be buffered andprocessed extends from the beginning of block 614 overlapping the startof the first slot 610 to the end of block 616 overlapping the end of thethird slot 610. However, as will be appreciated, this requires the UE tobuffer and process the entirety of the second slot 610, even thoughthere may not be any PRS received in that slot 610.

Assuming the slot-level buffering described above, in the set of slots‘S,’ any slot ‘s’ for which there is a potential PRS needs to becounted. In the interval [T_(S) ^(start), T_(S) ^(end)], T_(S) ^(start)should be rounded to the start of a symbol that is earlier than T_(S)^(start), and T_(S) ^(end) should be rounded to the end of a symbol thatis later than T_(S) ^(end). Accordingly, in an aspect, the slot-levelbuffering described above can be modified such that if a UE isconfigured by higher layers (e.g., LPP) to receive PRS symbols(regardless of the periodicity ‘P’) the symbol duration ‘K’ (i.e., thenumber of symbols that the UE needs to buffer/process in order tomeasure the PRS) is calculated by:

$K = {\sum\limits_{s \in S}^{\;}K_{S}}$

where ‘S’ is the smallest set of slots (not necessarily consecutive)within the PRS periodicity in the positioning frequency layer thatcontains all the potential PRS across TRPs, and where each potential PRSsymbol is determined by the parameters “nr-DL-PRS-ExpectedRSTD” and“nr-DL-PRS-ExpectedRSTD-Uncertainty” and the PRS symbol occupancy withinslot ‘s.’ The parameter μ remains the numerology of the PRS resources inthe positioning frequency layer, and N_(symb) ^(slot) remains the numberof symbols per slot. However, [T_(S) ^(start), T_(S) ^(end)] is thesmallest integer number interval of OFDM symbols for the givennumerology μ within slot ‘s’ that covers the union of the potential PRSsymbols from all cells/TRPs, where each potential PRS symbol isdetermined by the parameter “nr-DL-PRS-ExpectedRSTD,”“nr-DL-PRS-ExpectedRSTD-Uncertainty,” and the PRS symbol occupancywithin slot ‘s.’

When using integer values in the previous equation, the previousequation simplifies to:

${K = {\sum\limits_{s \in S}K_{S}}}{K_{S} = {T_{S}^{end} - T_{S}^{start}}}$

FIG. 7 is a diagram 700 illustrating an example of slot-based bufferingwith OFDM symbol alignment towards the largest interval that containsthe potential PRS in a slot, according to aspects of the disclosure.FIG. 7 illustrates a single slot 710 during which a UE expects toreceive/measure PRS from a reference cell (or TRP) and a neighbor cell(or TRP). As in FIG. 6, each block illustrated in FIG. 7 represents aduration of symbols during which the UE expects to receive the PRS fromthe respective cell. For the reference cell, the UE expects to receivePRS from that cell during block 712. Because of the uncertainty of whenthe UE may receive PRS from a neighboring cell (as indicated by“nr-DL-PRS-ExpectedRSTD-Uncertainty”), the PRS from the neighboring cellare illustrated as two different blocks, block 714, representing theearliest time period the UE expects to receive the PRS from theneighboring cell, and block 716, representing the latest point in timethe UE expects to receive the PRS from the neighboring cell. As will beappreciated, the UE may receive PRS from the neighboring cell at anytime between the start of block 714 and the end of block 716.

As shown in FIG. 7, based on the above slot-based buffering with OFDMsymbol alignment towards the largest interval that contains thepotential PRS in the slot 710, the PRS symbol duration 720 to bebuffered in a symbol-aligned manner extends from the start of the symbolthat includes the beginning of block 714, representing the earliestpoint in time the UE expects to receive the PRS from the neighboringcell, and extending to the end of the last symbol of block 716,representing the latest point in time the UE expects to receive the PRSfrom the neighboring cell.

FIG. 8 is a diagram 800 illustrating another example of slot-basedbuffering with OFDM symbol alignment towards the largest interval thatcontains the potential PRS in a slot, according to aspects of thedisclosure. FIG. 8 illustrates three consecutive slots 810 during whicha UE expects to receive/measure PRS from a reference cell (or TRP) and aneighbor cell (or TRP). As in FIG. 6, each block illustrated in FIG. 8represents a duration of symbols during which the UE expects to receivethe PRS from the respective cell. For the reference cell, the UE expectsto receive PRS from that cell during block 812. Because of theuncertainty of when the UE may receive PRS from a neighboring cell (asindicated by “nr-DL-PRS-ExpectedRSTD-Uncertainty”), the PRS from theneighboring cell are illustrated as two different blocks, block 814,representing the earliest point in time the UE expects to receive thePRS from the neighboring cell, and block 816, representing the latestpoint in time the UE expects to receive the PRS from the neighboringcell. As will be appreciated, the UE may receive PRS from theneighboring cell at any time between the start of block 814 and the endof block 816.

In contrast to the example of FIG. 6, there are two durations 820 of PRSsymbols to be buffered and processed, the first extending from thebeginning of block 714 overlapping the start of the first slot 810 tothe end of block 816 extending into the second slot 810, and the secondextending from the beginning of block 814 starting in the second slot810 to the end of block 816 extending past the end of the third slot810.

In some cases, a UE may be expected to perform resource-specificbuffering. If the UE is configured by higher layers to receive PRSsymbols in a frequency layer i, the duration of PRS symbols for thepurpose of the UE's PRS processing capability within a ‘T’ ms window iscomputed as follows. For each ‘T’ ms window, determine the time-domainsearch window of a PRS instance of a PRS resource j as S_(j)=[T_(start)^(j), T_(end) ^(j)], where [T_(start) ^(j), T_(end) ^(j)] is thesmallest interval in an integer number of OFDM symbols for thenumerology μ of the positioning frequency layer, which includes theinterval determined by “nr-DL-PRS-ExpectedRSTD,”“nr-DL-PRS-ExpectedRSTD-Uncertainty,” and the configured PRS symboloccupancy. The union of search windows across all resources of apositioning frequency layer, that is, the number of PRS symbols the UEis expected to buffer within the ‘T’ ms window, denoted as S_(layer)^((i)), is equal to:

$S_{layer}^{(i)} = {\bigcup\limits_{j \in N_{resources}}S_{j}}$

The PRS duration inside the ‘T’ ms window is the duration of S_(layer)^((i)).

If a UE is configured by higher layers to receive PRS symbols in afrequency layer i, the duration of PRS symbols for the purpose of PRSprocessing capability within a ‘T’ ms window is computed as follows. Foreach ‘T’ ms window, determine the time-domain search window of a PRSinstance of a PRS resource j as S_(j)=[T_(start) ^(j), T_(end) ^(j)],where, for a PRS resource from a neighboring TRP, [T_(start) ^(j),T_(end) ^(j)] is the smallest interval in an integer number of OFDMsymbols for the numerology μ of the positioning frequency layer thatincludes the interval determined by “nr-DL-PRS-ExpectedRSTD,”“nr-DL-PRS-ExpectedRSTD-Uncertainty,” and the configured PRS symboloccupancy. For a PRS resource from the reference TRP, [T_(start) ^(j),T_(end) ^(j)] is the smallest interval in an integer number of OFDMsymbols for the numerology μ of the positioning frequency layer thatincludes the interval determined by the configured PRS symbol occupancy.The union of search windows across all resources of a positioningfrequency layer, that is, the number of PRS symbols the UE is expectedto buffer within the ‘T’ ms window, denoted as S_(layer) ^((i)), isequal to:

$S_{layer}^{(i)} = {\bigcup\limits_{j \in N_{resources}}S_{j}}$

The PRS duration inside the ‘T’ ms window is the duration of S_(layer)^((i)).

FIG. 9 is a diagram 900 illustrating an example of a symbol-level PRSduration to be buffered, according to aspects of the disclosure. Eachblock illustrated in FIG. 9 represents a duration of symbols duringwhich the UE expects to receive the PRS from the respective cell. Thismay also be referred to as the expected PRS symbol occupancy within theslot 910 for that cell. For the reference cell, the UE expects toreceive PRS from that cell during block 912. As in the above figures,because of the uncertainty of when the UE may receive PRS from aneighboring cell, the PRS from a neighboring cell are illustrated as twodifferent blocks, block 914, representing the earliest point in time theUE expects to receive the PRS from the neighboring cell, and block 916,representing the latest point in time the UE expects to receive the PRSfrom the neighboring cell. As will be appreciated, the UE may receivePRS from the neighboring cell at any time between the start of block 914and the end of block 916. In addition, the three neighboring cellsreferred to in FIG. 9 may be the same neighboring cell or differentneighboring cells.

In the example of FIG. 9, the vertical lines represent the expected PRSsymbol occupancy within the slot 910 for a particular cell (i.e., theduration 920 of PRS symbols during which the UE expects to receive PRSfrom a cell). In the example of FIG. 9, there are four such durations920. The number of PRS symbols the UE is expected to buffer is thereforethe sum of the four PRS durations 920.

FIG. 10 is a diagram 1000 illustrating another example of a symbol-levelPRS duration to be buffered, according to aspects of the disclosure. Asin the above figures, each block illustrated in FIG. 10 represents aduration of symbols during which the UE expects to receive the PRS fromthe respective cell. For the reference cell, the UE expects to receivePRS from that cell during block 1012. Because of the uncertainty of whenthe UE may receive PRS from a neighboring cell, the PRS from aneighboring cell are illustrated as two different blocks, block 1014,representing the earliest point in time the UE expects to receive thePRS from the neighboring cell, and block 1016, representing the latestpoint in time the UE expects to receive the PRS from the neighboringcell. As will be appreciated, the UE may receive PRS from theneighboring cell at any time between the start of a block 1014 and theend of a block 1016 within the slot 1010. In addition, the threeneighboring cells referred to in FIG. 10 may be the same neighboringcell or different neighboring cells.

In the example of FIG. 10, the vertical lines represent the expected PRSsymbol occupancy within the slot 1010 for a particular cell (i.e., theduration 1020 of PRS symbols during which the UE expects to receive PRSfrom a cell). In the example of FIG. 10, there are three such durations1020, as the PRS expected from the reference cell overlap with the PRSexpected from one of the neighbor cells. The number of PRS symbols theUE is expected to buffer is therefore the sum of the three PRS durations1020.

As another alternative for slot-level buffering, if any slot containsany potential PRS symbol (based on the“nr-DL-PRS-ExpectedRSTD-Uncertainty” parameter), then the whole slot iscounted as part of the PRS duration for the purpose of the bufferingcomputation. In this case, inside a slot, the interval of the PRSduration can either be: (1) the union of [0, T1] and [T2, slot-End] fora slot that has two disjoint intervals with potential PRS symbols at thestart and end of the slot (as shown in FIG. 11), or (2) [T_(S) ^(start),T_(S) ^(end)] otherwise (as described above).

FIG. 11 is a diagram 1100 illustrating an example of slot-basedbuffering for a slot that has two disjoint intervals with potential PRSsymbols at the start and end of the slot, according to aspects of thedisclosure. FIG. 11 illustrates three consecutive slots 1110 duringwhich a UE expects to receive/measure PRS from a reference cell (or TRP)and a neighbor cell (or TRP). As in the figures described above, eachblock illustrated in FIG. 11 represents a duration of symbols duringwhich the UE expects to receive PRS from the respective cell. For thereference cell, the UE expects to receive PRS from that cell duringblock 1112. Because of the uncertainty of when the UE may receive PRSfrom a neighboring cell (as indicated by“nr-DL-PRS-ExpectedRSTD-Uncertainty”), the PRS from the neighboring cellare illustrated as two different blocks, block 1114, representing theearliest point in time the UE expects to receive the PRS from theneighboring cell, and block 1116, representing the latest point in timethe UE expects to receive the PRS from the neighboring cell. As will beappreciated, the UE may receive PRS from the neighboring cell at anytime between the start of block 1114 and the end block 1116 in a slot1110.

In the example of FIG. 11, there are two PRS symbol durations 1120 to bebuffered and processed, the first extending from the beginning of block1114 overlapping the start of the first slot 1110 to the end of block1116 in the second slot 1110, and the second extending from thebeginning of block 1114 in the second slot 1110 to the end of block 1116extending past the end of the third slot 1110.

As shown in FIG. 11, the second (middle) slot 1110 includes two disjointintervals with potential PRS symbols at the start and end of the slot1110. Based on the above rule, the time window during which the UE willbuffer the expected PRS for the second slot 1110 corresponds to thestart of the second slot 1110 to time ‘T1’ and from time ‘T2’ to the endof the second slot 1110. In contrast, the UE determines the duration1120 of PRS symbols for the first slot 1110 as [T_(S) ^(start), T_(S)^(end)], where T_(S) ^(start) is one or more symbols before the start ofthe first slot 1110 (corresponding to the vertical dashed line beforethe start of the first slot) and T_(S) ^(end) is the last symbol of thefirst slot 1110. Likewise, the UE determines the duration 1120 of PRSsymbols for the third slot 1110 as [T_(S) ^(start), T_(S) ^(end)], whereT_(S) ^(start) is the first symbol of the third slot 1110 and T_(S)^(end) is one or more symbols after the end of the third slot 1110(corresponding to the vertical dashed line after the end of the thirdslot 1110).

In an aspect, a UE may report, as a capability of the UE, how the DL-PRSduration is determined for the purpose of PRS buffering. That is, the UEmay transmit an indication of whether it is capable of symbol-level orslot-level PRS buffering and processing. A UE may report this capabilityto the location server (e.g., location server 230, LMF 270, SLP 272) inhigher layer signaling (e.g., LPP signaling).

FIG. 12 illustrates an example method 1200 of wireless communication,according to aspects of the disclosure. In an aspect, method 1200 may beperformed by a UE (e.g., any of the UEs described herein).

At 1210, the UE receives at least one PRS resource from a reference TRPand one or more neighboring TRPs. In an aspect, operation 1210 may beperformed by the at least one WWAN transceiver 310, the at least oneprocessor 332, memory component 340, and/or positioning component 342,any or all of which may be considered means for performing thisoperation.

At 1220, the UE processes the at least one PRS resource during a timewindow, wherein a length of the time window is less than or equal to aninteger number of OFDM symbols of the at least one PRS resource that theUE is capable of processing, buffering, or both within the time window.In an aspect, operation 1220 may be performed by the at least one WWANtransceiver 310, the at least one processor 332, memory component 340,and/or positioning component 342, any or all of which may be consideredmeans for performing this operation.

As will be appreciated, technical advantages of the method 1200 includereduced power consumption at the UE and reduced latency.

In the detailed description above it can be seen that different featuresare grouped together in examples. This manner of disclosure should notbe understood as an intention that the example clauses have morefeatures than are explicitly mentioned in each clause. Rather, thevarious aspects of the disclosure may include fewer than all features ofan individual example clause disclosed. Therefore, the following clausesshould hereby be deemed to be incorporated in the description, whereineach clause by itself can stand as a separate example. Although eachdependent clause can refer in the clauses to a specific combination withone of the other clauses, the aspect(s) of that dependent clause are notlimited to the specific combination. It will be appreciated that otherexample clauses can also include a combination of the dependent clauseaspect(s) with the subject matter of any other dependent clause orindependent clause or a combination of any feature with other dependentand independent clauses. The various aspects disclosed herein expresslyinclude these combinations, unless it is explicitly expressed or can bereadily inferred that a specific combination is not intended (e.g.,contradictory aspects, such as defining an element as both an insulatorand a conductor). Furthermore, it is also intended that aspects of aclause can be included in any other independent clause, even if theclause is not directly dependent on the independent clause.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of wireless communication performed by a userequipment (UE), comprising: receiving at least one positioning referencesignal (PRS) resource from a reference transmission-reception point(TRP) and one or more neighboring TRPs; and processing the at least onePRS resource during a time window, wherein a length of the time windowis less than or equal to an integer number of orthogonal frequencydivision multiplexing (OFDM) symbols of the at least one PRS resourcethat the UE is capable of processing, buffering, or both within the timewindow.

Clause 2. The method of clause 1, wherein the integer number of OFDMsymbols is determined based on a positioning frequency layer of the atleast one PRS resource.

Clause 3. The method of any of clauses 1 to 2, wherein the length of thetime window is based on a numerology of the at least one PRS resourceand a smallest interval of the integer number of OFDM symbols for thenumerology within a slot that covers a union of potential PRS symbols.

Clause 4. The method of any of clauses 1 to 3, wherein the time windowis calculated as:

${{K = {\sum\limits_{s \in S}K_{S}}}{K_{S} = {T_{S}^{end} - T_{S}^{start}}}},$

where S is a set of slots within a periodicity of PRS in a positioningfrequency layer that contains potential PRS, μ is a numerology of PRSresources in the positioning frequency layer, and [T_(S) ^(start), T_(S)^(end)] is an interval of the integer number of OFDM symbols for thenumerology μ within slot s that covers a union of potential PRS symbols.

Clause 5. The method of clause 4, wherein the set of slots is determinedbased on an expected reference signal time difference (RSTD) parameterand an expected RSTD uncertainty parameter for the one or moreneighboring cells, and a PRS symbol occupancy within slot s.

Clause 6. The method of any of clauses 4 to 5, wherein the interval ofthe integer number of OFDM symbols for the numerology μ is based on anexpected RSTD parameter and an expected RSTD uncertainty parameter forthe one or more neighboring cells, and a PRS symbol occupancy withinslot s.

Clause 7. The method of any of clauses 4 to 6, wherein a potential PRScomprises a PRS that is expected to be received within a duration ofsymbols based on an expected RSTD parameter and an expected RSTDuncertainty parameter for the one or more neighboring cells, and a PRSsymbol occupancy within slot s.

Clause 8. The method of any of clauses 1 to 7, further comprising:determining a time-domain search window of a PRS resource j of the atleast one PRS resource as S_(j)=[T_(start) ^(j), T_(end) ^(j)], where:for a PRS resource from a neighboring TRP of the one or more neighboringTRPs, [T_(start) ^(j), T_(end) ^(j)] is a smallest interval of theinteger number of OFDM symbols for a numerology μ of a positioningfrequency layer that includes an interval based on an expected RSTDparameter and an expected RSTD uncertainty parameter for the one or moreneighboring cells, and a configured PRS symbol occupancy of a slot, andfor a PRS resource from the reference TRP, [T_(start) ^(j), T_(end)^(j)] is a smallest interval of the integer number of OFDM symbols forthe numerology μ of the positioning frequency layer that includes aninterval determined by the configured PRS symbol occupancy of the slot.

Clause 9. The method of clause 8, wherein the integer number of OFDMsymbols is a union of time-domain search windows across all resources ofa positioning frequency layer.

Clause 10. The method of any of clauses 1 to 9, wherein, based on a slotcontaining any potential PRS symbols, all symbols of the slot areincluded in the integer number of OFDM symbols.

Clause 11. The method of any of clauses 1 to 10, wherein, for a slotthat contains two or more disjoint intervals with potential PRS symbols,the integer number of OFDM symbols comprises a union of a duration froma first symbol of the slot to a last symbol of a first PRS resourceexpected to be received during the slot and a duration from a secondsymbol of the slot during which a first symbol of a second PRS resourceis expected to be received to a last symbol of the slot.

Clause 12. The method of any of clauses 1 to 11, wherein, for a slotthat does not contain two or more disjoint intervals with potential PRSsymbols, the integer number of OFDM symbols comprises a first symbol ofthe slot during which PRS are expected to be received to a last symbolof the slot during which PRS are expected to be received.

Clause 13. The method of any of clauses 1 to 12, further comprising:transmitting, to a location server, an indication of the integer numberof OFDM symbols as a capability of the UE.

Clause 14. The method of any of clauses 1 to 13, further comprising:transmitting, to a location server, an indication of whether the UE iscapable of symbol-level or slot-level PRS buffering.

Clause 15. An apparatus comprising a memory, a transceiver, and at leastone processor communicatively coupled to the memory and the transceiver,the memory, the transceiver, and the processor configured to perform amethod according to any of clauses 1 to 14.

Clause 16. An apparatus comprising means for performing a methodaccording to any of clauses 1 to 14.

Clause 17. A non-transitory computer-readable medium storingcomputer-executable instructions, the computer-executable comprising atleast one instruction for causing a computer or processor to perform amethod according to any of clauses 1 to 14.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an ASIC, a field-programmable gate array (FPGA), or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,for example, a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An example storage medium is coupled to the processor such thatthe processor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal (e.g., UE). In thealternative, the processor and the storage medium may reside as discretecomponents in a user terminal.

In one or more example aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), comprising: receiving at least one positioningreference signal (PRS) resource from a reference transmission-receptionpoint (TRP) and one or more neighboring TRPs; and processing the atleast one PRS resource during a time window, wherein a length of thetime window is less than or equal to an integer number of orthogonalfrequency division multiplexing (OFDM) symbols of the at least one PRSresource that the UE is capable of processing, buffering, or both withinthe time window.
 2. The method of claim 1, wherein the integer number ofOFDM symbols is determined based on a positioning frequency layer of theat least one PRS resource.
 3. The method of claim 1, wherein the lengthof the time window is based on a numerology of the at least one PRSresource and a smallest interval of the integer number of OFDM symbolsfor the numerology within a slot that covers a union of potential PRSsymbols.
 4. The method of claim 1, wherein the time window is calculatedas: $K = {\sum\limits_{s \in S}K_{S}}$K_(S) = T_(S)^(end) − T_(S)^(start), where S is a set of slots within aperiodicity of PRS in a positioning frequency layer that containspotential PRS, μ is a numerology of PRS resources in the positioningfrequency layer, and [T_(S) ^(start), T_(S) ^(end)] is an interval ofthe integer number of OFDM symbols for the numerology μ within slot sthat covers a union of potential PRS symbols.
 5. The method of claim 4,wherein the set of slots is determined based on an expected referencesignal time difference (RSTD) parameter and an expected RSTD uncertaintyparameter for the one or more neighboring cells, and a PRS symboloccupancy within slot s.
 6. The method of claim 4, wherein the intervalof the integer number of OFDM symbols for the numerology μ is based onan expected RSTD parameter and an expected RSTD uncertainty parameterfor the one or more neighboring cells, and a PRS symbol occupancy withinslot s.
 7. The method of claim 4, wherein a potential PRS comprises aPRS that is expected to be received within a duration of symbols basedon an expected RSTD parameter and an expected RSTD uncertainty parameterfor the one or more neighboring cells, and a PRS symbol occupancy withinslot s.
 8. The method of claim 1, further comprising: determining atime-domain search window of a PRS resource j of the at least one PRSresource as S_(j)=[T_(start) ^(j), T_(end) ^(j)], where: for a PRSresource from a neighboring TRP of the one or more neighboring TRPs,[T_(start) ^(j), T_(end) ^(j)] is a smallest interval of the integernumber of OFDM symbols for a numerology μ of a positioning frequencylayer that includes an interval based on an expected RSTD parameter andan expected RSTD uncertainty parameter for the one or more neighboringcells, and a configured PRS symbol occupancy of a slot, and for a PRSresource from the reference TRP, [T_(start) ^(j), T_(end) ^(j)] is asmallest interval of the integer number of OFDM symbols for thenumerology μ of the positioning frequency layer that includes aninterval determined by the configured PRS symbol occupancy of the slot.9. The method of claim 8, wherein the integer number of OFDM symbols isa union of time-domain search windows across all resources of apositioning frequency layer.
 10. The method of claim 1, wherein, basedon a slot containing any potential PRS symbols, all symbols of the slotare included in the integer number of OFDM symbols.
 11. The method ofclaim 1, wherein, for a slot that contains two or more disjointintervals with potential PRS symbols, the integer number of OFDM symbolscomprises a union of a duration from a first symbol of the slot to alast symbol of a first PRS resource expected to be received during theslot and a duration from a second symbol of the slot during which afirst symbol of a second PRS resource is expected to be received to alast symbol of the slot.
 12. The method of claim 1, wherein, for a slotthat does not contain two or more disjoint intervals with potential PRSsymbols, the integer number of OFDM symbols comprises a first symbol ofthe slot during which PRS are expected to be received to a last symbolof the slot during which PRS are expected to be received.
 13. The methodof claim 1, further comprising: transmitting, to a location server, anindication of the integer number of OFDM symbols as a capability of theUE.
 14. The method of claim 1, further comprising: transmitting, to alocation server, an indication of whether the UE is capable ofsymbol-level or slot-level PRS buffering.
 15. A user equipment (UE),comprising: a memory; a transceiver; and a processor communicativelycoupled to the memory and the transceiver, the processor configured to:receive, via the transceiver, at least one positioning reference signal(PRS) resource from a reference transmission-reception point (TRP) andone or more neighboring TRPs; and process the at least one PRS resourceduring a time window, wherein a length of the time window is less thanor equal to an integer number of orthogonal frequency divisionmultiplexing (OFDM) symbols of the at least one PRS resource that the UEis capable of processing, buffering, or both within the time window. 16.The UE of claim 15, wherein the integer number of OFDM symbols isdetermined based on a positioning frequency layer of the at least onePRS resource.
 17. The UE of claim 15, wherein the length of the timewindow is based on a numerology of the at least one PRS resource and asmallest interval of the integer number of OFDM symbols for thenumerology within a slot that covers a union of potential PRS symbols.18. The UE of claim 15, wherein the time window is calculated as:$K = {\sum\limits_{s \in S}K_{S}}$ K_(S) = T_(S)^(end) − T_(S)^(start),where S is a set of slots within a periodicity of PRS in a positioningfrequency layer that contains potential PRS, μ is a numerology of PRSresources in the positioning frequency layer, and [T_(S) ^(start), T_(S)^(end)] is an interval of the integer number of OFDM symbols for thenumerology μ within slot s that covers a union of potential PRS symbols.19. The UE of claim 18, wherein the set of slots is determined based onan expected reference signal time difference (RSTD) parameter and anexpected RSTD uncertainty parameter for the one or more neighboringcells, and a PRS symbol occupancy within slot s.
 20. The UE of claim 18,wherein the interval of the integer number of OFDM symbols for thenumerology μ is based on an expected RSTD parameter and an expected RSTDuncertainty parameter for the one or more neighboring cells, and a PRSsymbol occupancy within slot s.
 21. The UE of claim 18, wherein apotential PRS comprises a PRS that is expected to be received within aduration of symbols based on an expected RSTD parameter and an expectedRSTD uncertainty parameter for the one or more neighboring cells, and aPRS symbol occupancy within slot s.
 22. The UE of claim 15, wherein theprocessor is further configured to: determine a time-domain searchwindow of a PRS resource j of the at least one PRS resource asS_(j)=[T_(start) ^(j), T_(end) ^(j)], where: for a PRS resource from aneighboring TRP of the one or more neighboring TRPs, [T_(start) ^(j),T_(end) ^(j)] is a smallest interval of the integer number of OFDMsymbols for a numerology μ of a positioning frequency layer thatincludes an interval based on an expected RSTD parameter and an expectedRSTD uncertainty parameter for the one or more neighboring cells, and aconfigured PRS symbol occupancy of a slot, and for a PRS resource fromthe reference TRP, [T_(start) ^(j), T_(end) ^(j)] is a smallest intervalof the integer number of OFDM symbols for the numerology μ of thepositioning frequency layer that includes an interval determined by theconfigured PRS symbol occupancy of the slot.
 23. The UE of claim 22,wherein the integer number of OFDM symbols is a union of time-domainsearch windows across all resources of a positioning frequency layer.24. The UE of claim 15, wherein, based on a slot containing anypotential PRS symbols, all symbols of the slot are included in theinteger number of OFDM symbols.
 25. The UE of claim 15, wherein, for aslot that contains two or more disjoint intervals with potential PRSsymbols, the integer number of OFDM symbols comprises a union of aduration from a first symbol of the slot to a last symbol of a first PRSresource expected to be received during the slot and a duration from asecond symbol of the slot during which a first symbol of a second PRSresource is expected to be received to a last symbol of the slot. 26.The UE of claim 15, wherein, for a slot that does not contain two ormore disjoint intervals with potential PRS symbols, the integer numberof OFDM symbols comprises a first symbol of the slot during which PRSare expected to be received to a last symbol of the slot during whichPRS are expected to be received.
 27. The UE of claim 15, wherein theprocessor is further configured to: cause the transceiver to transmit,to a location server, an indication of the integer number of OFDMsymbols as a capability of the UE.
 28. The UE of claim 15, wherein theprocessor is further configured to: cause the transceiver to transmit,to a location server, an indication of whether the UE is capable ofsymbol-level or slot-level PRS buffering.
 29. A user equipment (UE),comprising: means for receiving at least one positioning referencesignal (PRS) resource from a reference transmission-reception point(TRP) and one or more neighboring TRPs; and means for processing the atleast one PRS resource during a time window, wherein a length of thetime window is less than or equal to an integer number of orthogonalfrequency division multiplexing (OFDM) symbols of the at least one PRSresource that the UE is capable of processing, buffering, or both withinthe time window.
 30. A non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a user equipment(UE), cause the UE to: receive at least one positioning reference signal(PRS) resource from a reference transmission-reception point (TRP) andone or more neighboring TRPs; and process the at least one PRS resourceduring a time window, wherein a length of the time window is less thanor equal to an integer number of orthogonal frequency divisionmultiplexing (OFDM) symbols of the at least one PRS resource that the UEis capable of processing, buffering, or both within the time window.